Fix compilation of pdumper.c with old buggy GCC

* src/pdumper.c (emacs_ptr_at): Renamed from emacs_ptr, to
avoid compilation errors with GCC 4.7.  Reported by Martin
Rudalics <>.  All callers changed.
1 job for master in 60 minutes (queued for 1 second)
Status Job ID Name Coverage
failed #627


Name Stage Failure
test-all Test The script exceeded the maximum execution time set for the job
  GEN      lisp/eshell/eshell-tests.log
ELC lisp/faces-tests.elc
GEN lisp/faces-tests.log
ELC lisp/ffap-tests.elc
GEN lisp/ffap-tests.log
ELC lisp/filenotify-tests.elc
GEN lisp/filenotify-tests.log
Pulling docker image gitlab/gitlab-runner-helper:x86_64-f100a208 ...
ERROR: Job failed: execution took longer than 1h0m0s seconds